glsl: Generate unique names for each const array lowered to uniforms

Uniform names (even for hidden uniforms) are required to be unique; some
parts of the compiler assume they can be looked up by name.

Fixes the piglit test: tests/spec/glsl-1.20/linker/array-initializers-1

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Cc: "10.4" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/glsl/lower_const_arrays_to_uniforms.cpp

diff --git a/src/glsl/lower_const_arrays_to_uniforms.cpp b/src/glsl/lower_const_arrays_to_uniforms.cpp
index b3c0ee2..700e903 100644
--- a/src/glsl/lower_const_arrays_to_uniforms.cpp
+++ b/src/glsl/lower_const_arrays_to_uniforms.cpp
@@ -49,6 +49,7 @@
    {
       instructions = insts;
       progress = false;
+      index = 0;
    }
 
    bool run()
@@ -62,6 +63,7 @@
 private:
    exec_list *instructions;
    bool progress;
+   unsigned index;
 };
 
 void
@@ -76,8 +78,10 @@
 
    void *mem_ctx = ralloc_parent(con);
 
+   char *uniform_name = ralloc_asprintf(mem_ctx, "constarray__%d", index++);
+
    ir_variable *uni =
-      new(mem_ctx) ir_variable(con->type, "constarray", ir_var_uniform);
+      new(mem_ctx) ir_variable(con->type, uniform_name, ir_var_uniform);
    uni->constant_initializer = con;
    uni->constant_value = con;
    uni->data.has_initializer = true;